Fluid product dispenser

ABSTRACT

A method of maintaining a fluid dispenser that includes a housing holding an assembly, including a liquid reservoir, a pump for dispensing the fluid product, and an outlet nozzle includes disconnecting the a compressor portion of the pump and substituting the disconnected compressor by a replacement compressor, wherein the replacement compressor has a different pressurizing volume to the replaced compressor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/894,960 filed Sep. 30, 2010, which claims benefit to U.S. ProvisionalApplication No. 61/248,622 filed Oct. 5, 2009 and claims priority toEuropean Application No.: 09012541.0 filed Oct. 4, 2009, each of whichis incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The invention relates generally to a dispenser for dispensing a fluidproduct and more particularly to a dispenser having a pump structure forproviding a dose of fluid product to a user.

BACKGROUND

For purposes of clarity and consistency, the following terms as usedthroughout this text and the appended claims should be interpreted asfollows:

-   -   The term “fluid” should be broadly interpreted as encompassing a        liquid, a suspension of a granulate solid in a liquid, a gel, a        foam, and a spray, for example.    -   The term “product” should be interpreted as encompassing soap        (including shower gel), shampoo, disinfectant, detergent,        moisturizer, hair conditioner, and exfoliating scrub, for        example, including mixtures of these substances.    -   The “liquid product” may be dispensed directly through the        outlet nozzle, or may first be mixed with another substance,        such as air or another gas, or a granulate solid, for example.    -   The term “pump” refers to any type of pump suitable under the        circumstances.        The pump in question may employ a piston, bellows, and/or        membrane, for example.        These points will be discussed in more detail below.

Fluid product dispensers of a type having a housing for accommodating anassembly, the assembly having a liquid reservoir for containing a liquidproduct, a pump, connectable to the reservoir, for dispensing the fluidproduct using the liquid product as an input, and an outlet nozzle,serving to convey and dispense the fluid product from the pump areknown. In a typical example, the pump includes a liquid chamber, forcontaining a dose of the liquid product, obtainable from the liquidreservoir, and a pressurizing device, which allows liquid product to bedrawn into or expelled from the liquid chamber. One example is describedin U.S. Pat. No. 5,445,288 (Deb). Such dispensers are, for example,employed in washrooms, toilets, kitchens, hospitals, surgeries,hair/beauty salons, workshops and factories. In many cases, suchdispensers are mounted to a wall, often in the vicinity of a basin,bath, shower or toilet bowl; alternatively, such dispensers may befree-standing, and may be placed on a shelf, worktop or wash hand basin,or a trolley. In use, the pressurizing device is typically operated byhand, arm or elbow (e.g., via a manual actuating organ, such as a leveror button) so as to dispense a quantity of fluid product. In manyapplications, this fluid product will be dispensed into the operator'shand, or onto a carrier such as a cloth, after which the fluid productis rubbed onto the skin, or is applied from said carrier onto a surfaceto be treated, such as a metal, ceramic or plastic surface to be cleanedand/or disinfected, for example. In practice, the liquid reservoir maybe collapsible (e.g., in the form of a plastic pouch) or (quasi-)rigid(e.g., in the case of a bottle or tub). As an alternative to a manualactuating organ, an actuating organ employing an electric actuator isalso possible; in this case, the electric actuator can be triggered by asignal from a detector that registers the presence of a member (such asa hand or cloth) onto which fluid is to be dispensed. This latteralternative is not disclosed in U.S. Pat. No. 5,445,288, but it relieson a generally known principle.

In the dispenser described in U.S. Pat. No. 5,445,288, the liquidchamber is accompanied by a co-operating (ancillary) air chamber, whichis provided with its own (ancillary) pressurizing device (a pistonarrangement in the case in hand). During a filling stroke, therespective pressurizing devices are used to “evacuate” the liquid andair chambers, thereby drawing a dose of liquid product into the liquidchamber from the attached liquid reservoir (through a hydraulic inletvalve), and drawing a dose of air into the air chamber (through apneumatic inlet valve). During an ensuing dispensing stroke, therespective pressurizing devices are used to “compress” the liquid andair chambers, whence their doses of liquid product and air aresimultaneously forced into the outlet nozzle, where they co-mingle in aturbulence-generating member (e.g., a sieve or mesh, a set ofsieves/meshes, a porous plug, etc.) to produce foam, which is dischargedthrough the outlet nozzle to the outside world.

In dispensers as set forth above, when the contents of the liquidreservoir are depleted, the whole assembly in the dispenser housing isreplaced, i.e., the old liquid reservoir with attached (used)pump/nozzle is discarded, and a new liquid reservoir with attached(unused) pump/nozzle is mounted in the housing. This has been found tobe necessary because, if only the liquid reservoir is replaced and thepump/nozzle is left in place, clogging of the dispenser can eventuallyoccur. Conventionally, such clogging has been (primarily) attributed tooxidation of traces of liquid product that remain in the pump during itsuse over an extended period of time. So, although such regularreplacement of the pump is a pity in terms of increased operationalcosts and environmental burden, it nevertheless is required in order toprevent malfunction of dispensers known from the prior-art.

SUMMARY

An aspect of an embodiment of the invention addresses this cloggingissue. More particularly, embodiments of the invention may provide adispenser with reduced operational costs. In particular, embodiments mayprovide a dispenser that involves less waste/environmental burden thancertain other dispensers.

In an embodiment, a dispenser in accordance with the invention includesa shunting chamber including a first aperture allowing flow access tothe liquid reservoir, a second aperture allowing flow access to theoutlet nozzle, and a third aperture allowing flow access to the liquidchamber. The third aperture is disposed off-axis with respect to thefirst and second apertures, and the shunting chamber further includes agoverning device that has two states, such that in a first state, afirst flow path is created between the first and third apertures and ina second state, a second flow path is created between the third andsecond apertures. The governing device is transitionable between the twostates by external mechanical action.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be elucidated in more detail on the basis ofexemplary embodiments and the accompanying schematic drawings, in which:

FIG. 1 renders a perspective view of a dispenser according to the priorart;

FIG. 2 shows a longitudinal cross-section of the subject of FIG. 1;

FIG. 3 shows a longitudinal cross-section of a prior-art foam pump,suitable for use in a dispenser according to the prior art;

FIGS. 4A and 4B show longitudinal cross-sectional views of part of anembodiment of a dispenser in accordance with the present invention;

FIGS. 5A and 5B show longitudinal cross-sectional views of part ofanother embodiment of a dispenser in accordance with the presentinvention;

FIG. 6 renders an end view of part of yet another embodiment of adispenser in accordance with the present invention;

FIG. 7 shows perspective views of various possible embodiments of partof the subject of FIGS. 6; and

FIGS. 8A and 8B render longitudinal cross-sectional views of part of yetanother embodiment of a dispenser in accordance with the currentinvention.

In the Figures, corresponding parts are indicated using correspondingreference symbols.

DETAILED DESCRIPTION

In research leading to the invention, the inventors arrived at theinsight that the clogging problems referred to above are most likely tooccur in the outlet nozzle rather than in the liquid chamber of thepump. This is because, in the former, fluid residue is generally presentas a thin film in the presence of a relatively large body of air, sothat there is a substantial fluid/air interface. The inventors thusrealized that replacement of just the outlet nozzle rather than theliquid chamber/pressurizing device would be an adequate measure toreduce the risk of clogging. However, in prior-art dispensers, replacingthe reservoir and outlet nozzle while re-using the liquidchamber/pressurizing device would involve a laborious and messydisassembly and re-assembly operation, requiring the use of tools (suchas screwdrivers or pliers), increasing the risk of damage to—and lossof—parts, and taking valuable time, as a janitor or other attendantwould need to spend several minutes opening, removing and replacingcomponents. In addition, such an operation would often need to beconducted standing up, with no practical surface to lay parts or toolson, and often with unsatisfactory lighting levels. The extended timerequired to perform the operation, and the very nature of thedisassembly and re-assembly, may increase the risk of leakage of liquidproduct onto floor areas.

To address these problems, the inventors designed a dispenserarchitecture in which the liquid chamber/pressurizing device are nolonger connected in series with the liquid reservoir and outlet nozzle,but are instead connected in a “shunt” or “side branch” arrangement. Asa result, the liquid chamber/pressurizing device are no longer “in line”with the liquid reservoir and outlet nozzle, and, accordingly, onedoesn't have to get them “out of the way” in order to replace the liquidreservoir and nozzle. Instead, the liquid reservoir/pressurizing devicecan be embodied as a fixture that remains behind in the housing, whilethe rest of the assembly is removably connected to the liquid chambervia the third aperture in the shunting chamber (e.g., using a simple anduser-friendly “click” fitting, or other convenient form of abutment anddocking). Since the rest of the pump is “out of the way” in this manner,one can form a disposable composite part comprising the liquid reservoirand outlet nozzle (and interposed shunting chamber), and this entirecomposite part can be removed and replaced with a minimum of effort andmess. In this way, one wastes fewer parts (most of the pump remainsbehind each time the liquid reservoir is replaced), thus incurring loweroperating costs and less refuse processing/environmental load.

However, providing the liquid chamber/pressurizing device in a “shunt”in this manner also has other potential advantages. In particular,because the liquid chamber/pressurizing device are no longer “in line”with the rest of the assembly, it becomes possible to use differentsizes of liquid pressurizing device (and, in the case of a foamdispenser, also different sizes of air pressurizing device) with a givendispenser/disposable composite part, without having to change thedimensioning of the housing. For example, in the specific case of a foamdispenser:

-   -   Proportionately altering the size (pressurizing volume) of the        employed liquid and air pressurizing devices will        correspondingly alter the total dose of foam per dispensing        action;    -   Disproportionately altering the size (pressurizing volume) of        the employed liquid and air pressurizing devices will        correspondingly alter the quality of the dispensed foam (by        altering the relative quantities of liquid product and air mixed        in each dispensing action).

In the case of “in-line” prior-art dispensers, such alteration is eitherimpossible or requires cumbersome modification of the housing and otherparts.

In an embodiment, the liquid chamber may be accompanied by an ancillarychamber. An example of such an ancillary chamber already referred toabove is an air chamber, as employed in a foam dispenser. However, theancillary chamber can also be embodied to contain substances other thanair—it might, for example, contain an ancillary liquid or granulatesolid to be mixed with the liquid product before being dispensed fromthe outlet nozzle, or it might contain a gas other than air; in theselatter cases, the ancillary chamber could be connected to its ownancillary reservoir containing a supply of the respective substance tobe fed to the ancillary chamber. When the dispenser according to theinvention comprises such an ancillary chamber in addition to the liquidchamber, it can be useful—e.g., with an eye to facilitating thealteration possibility described in the previous paragraph—to locate theliquid chamber and ancillary chamber side-by-side; in this way, it iseasy to alter either of the pressurizing devices associated with thechambers individually, or both of them together. A further aspect ofsuch a side-by-side configuration is that, because the liquid andancillary chambers are spaced from one another, there tends to be littleor no chemical “crosstalk” between them, such as a migration of reactivevapor out of the liquid chamber and into the ancillary chamber, where itmight have a detrimental chemical effect on the performance of a seal,for example. An alternative configuration involves a nested arrangementof the liquid chamber and ancillary chamber, e.g., a concentric/co-axialarrangement (as is described in a different context in U.S. Pat. No.5,445,288, for example, in which the liquid chamber is nested within anair chamber). This configuration does not demonstrate the “spaced apart”aspect of the aforementioned side-by-side arrangement, so it is possibleto make it relatively compact.

In the dispenser according to the invention, the governing device istransitioned between said two states by external mechanical actuation.By this is meant that the governing device does not change state as aresult of pneumatic, hydraulic or hydrostatic effects within theassembly, but is instead operated by external mechanical actuation,e.g., a mechanical connection to the actuating organ referred to aboveand below. Such an arrangement may exhibit several usefulcharacteristics. For example:

-   -   In an arrangement using hydrostatic (i.e., pressure-operated)        valves—such as in U.S. Pat. No. 5,445,288—squeezing the liquid        reservoir would tend to cause the valves to open, whereby liquid        product would undesirably flow out of the outlet nozzle. Such        squeezing could be inadvertently caused during reservoir        replacement, or as a result of incorrect mounting of the        reservoir in the housing, for example. In the case of a        governing device that is operated by external mechanical        actuation, this effect can be prevented, since squeezing the        liquid reservoir will generally not actuate the governing device        in such a set-up.    -   Hydrostatic valves only open when a sufficient pressure head has        built up. A small malfunction elsewhere in the apparatus (e.g.,        a leak, or a resilient part that has become “tired”) may prevent        sufficient pressure from building up, whence the valves will no        longer operate. Again, a governing device that is externally        mechanically actuated will not generally suffer from this        drawback.        In an exemplary aspect of the dispenser according to the current        invention, the governing device includes a single moving        structure that can be slid between said two states, said single        moving structure serving to alternately open and close said        first and second flow paths. In a particular embodiment of such        a dispenser:    -   the shunting chamber includes a cylindrical portion;    -   the governing device includes a plug that is slideably mounted        within the cylindrical portion, the plug being at least        partially hollow;    -   in the first state, the plug is in a position distal from the        first aperture, and the first flow path is along an external        surface of the plug;    -   in the second state, the plug is in a position proximal to the        first aperture, and the second flow path is through an interior        space of the plug via an entrance in a wall of the plug and an        exit in flow communication with the second aperture.        Because the liquid chamber is no longer in series with the        liquid reservoir and outlet nozzle, it can be accessed via a        single aperture (the above-mentioned third aperture), which acts        as both an inlet and an outlet for the liquid product. Because        there is only a single aperture in this manner, there is no need        for the two separate liquid valves employed in U.S. Pat. No.        5,445,288 (which uses two separate apertures in its liquid        chamber—an inlet aperture and a spaced-apart outlet aperture,        each with its own valve). The governing device in the current        invention can therefore take a totally different form to the        prior-art double-valve structure. In particular, the sliding        arrangement of the governing device specified in the previous        paragraph (and described in greater detail below: see, for        example, FIGS. 4A/4B and 8A/8B) has the following        characterisitcs:    -   There is only one moving part (not two—so there are fewer parts        to malfunction).    -   Since there is a single aperture serving both as inlet and        outlet for the liquid product to/from the liquid chamber, and        since the sliding plug allows only one of said two        (inlet/outlet) states to exist at any one time, it is impossible        for liquid product to flow continuously from the liquid        reservoir out of the outlet nozzle. In contrast, if the liquid        outlet valve in the dispenser set forth in U.S. Pat. No.        5,445,288 becomes jammed open (e.g., due to the presence of a        piece of grit in the valve, or failure of the valve biasing        spring), then the entire contents of the liquid reservoir will        flow through the open inlet and outlet valves and spill out of        the dispenser onto the floor below, which is a wasteful        situation.

Of course, one does not have to use a governing device as set forth inthe previous two paragraphs, and the skilled artisan will realize thatthere are many possible alternatives within the scope of the presentinvention. The skilled artisan will also understand how the governingdevice can suitably be transitioned between the aforementioned twostates. For example, a dispenser according to the current invention maycomprise an actuating organ that can be caused to actuate by an operatorand that is mechanically connected to said governing device so as toeffect said transition. Actuation of said actuating organ may be manualor electrical, for example.

It should be explicitly noted that the second aperture referred to inthis document need not be a static aperture in a fixed position in theshunting chamber; it can also be a dynamic aperture that moves withinthe shunting chamber, e.g., as in the case of an aperture associatedwith a governing device and/or outlet nozzle that slides within theshunting chamber (see, for example, FIGS. 4A and 4B). Moreover, in thecase of a governing device comprising a (partially) hollow plug havingan interior space, an exit of said interior space may coincide with saidsecond aperture and/or an entrance to said outlet nozzle (once again,see FIGS. 4A and 4B, for example).

As already set forth above, in the dispenser of the current invention,the fluid product dispensed from the outlet nozzle:

-   -   Can simply be the liquid product contained in the liquid        reservoir; or    -   Can be a foam, generated by mixing air (or another gas) with        said liquid product, as explained above (and as also described        in U.S. Pat. No. 5,445,288, for example); or    -   Can be a spray. In this latter case, the outlet nozzle comprises        a constriction arranged in a flow path of the fluid, and the        (pressurized) passage of the liquid product through this        constriction serves to generate said spray.

There are also other possibilities. For example, a granulate solid froma separate reservoir can be mixed with the liquid product to form asuspension that emerges from the outlet nozzle. In many cases, such agranulate solid can simply be present in the liquid product as stored inthe liquid reservoir, so that it does not have to be added separatelyduring the dispensing stroke of the dispenser; however, if the densityof the granulate solid and/or viscosity of the liquid product are suchthat the granulate solid would tend to “settle”, then it may be betterto add it separately during the dispensing stroke.

In the case of a foam dispenser employing an (ancillary) air chamber inaddition to the liquid chamber, the air chamber will have:

-   -   an air outlet that (ultimately) emerges into the outlet nozzle;        and    -   an air inlet, through which a dose of air can be sucked into the        air chamber.        In a particular embodiment of the dispenser according to the        invention, this air inlet:    -   is a passage other than the outlet nozzle;    -   is provided with a filter, such as a HEPA filter.        Certain aspects of such a configuration can be set forth as        follows:    -   drawing air into the air chamber through the outlet nozzle can        cause a certain amount of foam residue present in the outlet        nozzle to be drawn into the air chamber. The presence of such        foam residue in the air chamber can be undesirable for a number        of reasons. For example:        -   it can produce a chemical attack on structural parts, such            as seals or other resilient members;        -   it can oxidize and coagulate, causing congestion/clogging;        -   it can become septic, thus compromising hygiene.

Where possible, it is advantageous to avoid such risks, as in the caseof an air inlet that is disparate from the outlet nozzle.

-   -   Drawing air into the air chamber through a filter such as a HEPA        filter serves to further improve aseptic performance of the        dispenser, since the presence of contaminants in the air used by        the dispenser will thus be countered.

The skilled artisan will appreciate that there are many satisfactoryways of embodying such a separate/dedicated air inlet.

A separate/dedicated air inlet in an air chamber of a foam dispenser asset forth in the previous paragraph is of particular importance if, inaccordance with the current invention:

-   -   the liquid chamber and air chamber and their associated        pressurizing devices are mounted as fixtures in the housing, and    -   the liquid reservoir and outlet nozzle are removably mountable        as disposable components in the housing.

If the liquid/air chambers were merely to be discarded with thereservoir in accordance with the prior art, then the issues set forth inthe previous paragraph would be of somewhat lesser importance, since theliquid/air chambers would be regularly replaced. However, when theliquid/air chambers remain in place, issues of chemical degradation ofparts, coagulation/clogging and septic contamination in the air chamberbecome much more significant, and need to be stringently mitigated.

As regards the pressurizing device(s) alluded to above and in theappended claims, the skilled artisan will be able to recognize andachieve many possible embodiments within the sphere of his knowledge andthe scope of his ability. For example, the pressurizing device(s) mayemploy:

(i) A piston principle. In this case, the liquid chamber (and/orancillary chamber) may be embodied as a cylindrical tube in which aplunger can be axially moved. An actuating organ as referred to abovecan then be connected to this plunger, for example.

(ii) A bellows principle. In this case, the wall of the liquid chamber(and/or ancillary chamber) is embodied to be flexible and collapsible,as in the case of a concertina arrangement or balloon arrangement. Theabove-mentioned actuating organ can then be connected to an extremity ofthis bellows, serving to move it toward and away from an oppositeextremity of the bellows.

(iii) A membrane principle. In this case, only a portion of the liquidchamber (and/or ancillary chamber)—e.g., one of its walls—is embodied asa flexible sheath (“membrane”). Said actuating organ can then beconnected to this sheath.

As an alternative to these possibilities, one could conceive apressurizing device employing an impeller, for example.

It should be noted that, in a pressurizing device relying on a bellowsprinciple as alluded to in item (ii) of the previous paragraph, aparticular embodiment of the present invention is characterized in thatthe bellows involved is biased in an extended state using an externalspring device. A bellows can be embodied to be self-biasing to someextent (e.g., when it takes the form of a concertina structurecomprising a resilient material such as plastic); however, when such abellows is used for a relatively long time, and particularly when it isexposed to a relatively “harsh” chemical environment (e.g., in pumpingsoaps, detergents, disinfectants, or other such substances), there is adanger that the bellows will become “tired”, and will lose itsself-biasing characteristics to a lesser or greater extent. To mitigatesuch an effect, any intrinsic self-biasing tendency of the bellows ispreferably augmented using extrinsic biasing on the basis of an externalspring device. For example, a coil spring or leaf spring can be anchoredin the housing and attached to the bellows in such a way that it tendsto urge the bellows into its extended state (corresponding to relativelylarge internal volume), e.g., when a dispensing stroke is finished(during which the bellows attains a relatively small internal volume).

Example 1 (Prior Art)

FIG. 1 renders a schematic perspective view of part of a dispenser 1 fordispensing a fluid product, in accordance with the prior art.

FIG. 1 shows a housing 3, which can be mounted to a wall of a washroom,for example. The housing 3 accommodates an assembly C that comprises aliquid reservoir 20, for containing a liquid product, an attached pump22, and an outlet nozzle 24; these items are only visible in FIG. 2, andwill be discussed later in more detail. An actuating organ 14 isincorporated in the housing 3, and can be actuated so as to operate saidpump 22. Also shown are an inspection window W, which allows the amountof liquid product in the liquid reservoir 20 to be seen from outside. Anaperture 18 allows insertion of a tool with the aid of which the housing3 can be unlocked and opened, allowing access to the assembly C (liquidreservoir 20+pump 22+outlet nozzle 24) located within. The housing 3 ismade from any suitable rigid material, such as metal or a plastic, forexample.

FIG. 2 renders a cross-sectional view of the subject of FIG. 1, takenalong the line 2-2. The liquid reservoir 20 is now visible, and is hereembodied as a flexible plastic container, such as a pouch. The liquidproduct contained in the reservoir 20 may, for example, comprise soap,shower/bath gel, detergent, disinfectant, exfoliating scrub, or mixturesof (certain of) these products.

A pump 22 is attached to the underside of the liquid reservoir 20, so asto be able to draw liquid product from within the liquid reservoir 20.The pump 22 may be any suitable type of pump for the application inquestion, such as a liquid pump, spray pump or foam pump, for example,and may operate on the basis of a movable piston, bellows and/ormembrane, for example. In operation, the pump 22 may directly dispensethe liquid contained within the reservoir 20, or may first mix it withair to form a spray or foam, for example. In all cases, the pump 22dispenses a fluid product from the outlet nozzle 24. More informationwith regard to pumps suitable for use in this type of application can,for example, be gleaned from U.S. Pat. No. 5,271,530 (Daiwa Can Company)and US 2004/0149777 A (Taplast)—which are incorporated herein byreference—and from the website www.airspray.nl.

As can be seen in FIG. 2, the actuating organ 14 in this instance ishinged to the housing 3 via a hinge joint 26. This, together with thegap 28 below the actuating organ 14, ensures that the actuating organ 14can be swung in and out of the housing 3. An arm 30 connects theactuating organ 14 to the pump 22 in such a manner that, when theactuating organ 14 is swung into the housing 3 about hinge joint 26, arm30 operates pump 22 so as to dispense a dose of fluid product throughthe outlet nozzle 24. A biasing device, such as a spring 32, ensuresthat the actuating organ 14 is urged back into its swung-out positionwhen released. In many applications, a user depresses the actuatingorgan 14 using his hand palm, lower arm or elbow, for example, andcollects the fluid product dispensed from the outlet nozzle 24 in hishand or on a carrier (such as a cloth or tissue); in such applications,the outlet nozzle 24 will generally face substantially downward.

The pump 22 is removably mounted to a bracket 36 that protrudes from theback wall 34 of the housing 3. This back wall 34 can be provided withscrew-holes, magnets, or other means for mounting it to a wall or othersurface. Also protruding from the back wall 34 is a lug 38B, which gripsa cooperating lug 38A; using a tool inserted through aperture 18, thesetwo lugs 38A, 38B can be disengaged, allowing the housing 3 to be openedso as to replace the assembly C inside when the liquid reservoir 20 hasbecome depleted.

Example 2 (Prior Art)

In the set-up depicted in FIG. 2, and in the dispensers disclosed in allof the above-mentioned prior-art documents (U.S. Pat. No. 5,445,288,U.S. Pat. No. 5,271,530, US 2004/0149777 A), the pump 22 has an“on-axis” or “in-line” architecture. This terminology will be elucidatedin more detail below, but, first, the general structure of such a pumpwill be briefly discussed.

FIG. 3 shows a longitudinal cross-section of a prior-art foam pump 122,which can be used to provide the functionality of pump 22 in FIG. 2, forexample. The pump 122 comprises:

-   -   A liquid chamber 102 for containing a dose of liquid product.    -   A pressurizing device 108, 108′, 111 (in this case, a piston        arrangement), which allows liquid product to be drawn into or        expelled from the liquid chamber 102.    -   A liquid inlet valve 104 for admitting a dose of liquid product        into the liquid chamber 102. Such admission occurs through an        inlet passage 125 that can be connected to a liquid reservoir        (not depicted, but analogous to item 20 in FIG. 2).    -   A liquid outlet valve 106 for regulating passage of liquid        product from the liquid chamber 102 to outlet nozzle 124.        Also present are:    -   An ancillary chamber 110, which in the current case is an air        chamber for containing a dose of air.    -   An ancillary pressurizing device 116 (in this case, a bellows        arrangement), which allows air to be drawn into or expelled from        the ancillary chamber 110.    -   An air inlet valve 112, for admitting air into the air chamber        110.    -   An air outlet device 127, for conducting air from the air        chamber 110 to outlet nozzle 124.    -   A member 118 for generating turbulence in fluid passing        therethrough (whereby it should be explicitly noted that the        member 118 may have a composite structure, e.g., comprising a        series arrangement of two or more sieves/meshes).        In the illustrated embodiment, the following design choices have        been made:    -   The pressurizing device 108, 108′, 111 is embodied as a piston,        with a piston shaft 111 and an attached piston head 108, which        can be moved telescopically in and out of a piston tube 108′.        The piston shaft 111 is hollow, and has a central passage that        forms part of the liquid chamber 102. Moving dispensing head 105        toward collar 107 causes the piston head 108 to start a        compression stroke, applying pressure to a body of liquid        product present in the liquid chamber 102, and thus forcing        liquid product from the liquid chamber 102 through the liquid        outlet valve 106. On the other hand, moving dispensing head 105        away from collar 107 causes the piston 108 head to start a        relaxation stroke, causing negative pressure to build up in the        (empty) liquid chamber 102. If desired, elastic biasing means        (such as a spring) can be employed to ensure that the piston        head 108 starts its relaxation stroke of its own accord once it        is released from its compression stroke.    -   The ancillary pressurizing device 116 is embodied as a bellows,        within which air chamber 110 is located. Moving dispensing head        105 toward collar 107 compresses the bellows 116, reducing the        volume of the air chamber 110 and thus forcing air from the air        chamber 110 through the air outlet device 127. On the other        hand, moving dispensing head 105 away from collar 107 causes the        bellows 110 to relax, whereby air will be sucked into the        bellows 110 through the air inlet valve 112. If the bellows 110        is made of resilient material, such as flexible plastic or        rubber, it will be self-relaxing.    -   The liquid chamber 102 and air chamber 110 are in nested,        co-axial arrangement.        The skilled artisan will appreciate that these are free design        choices, and that other worthy alternatives are available, as        alluded to earlier in this text.

In FIG. 3, the liquid chamber 102 is in an “on-axis” or “in-line”configuration, in the sense that the liquid chamber 102 is disposed inseries arrangement with the liquid inlet valve 104 and the liquid outletvalve 106. Consequently, if one wants to dispose of the outlet nozzle124 and the liquid reservoir (20; not shown) connected to inlet passage125, but wants to leave behind the liquid chamber 102 and associatedpressurizing device 108, 108′, 111, then the pump 122 will have to bedisassembled, in a cumbersome and time-consuming fashion.

Embodiment 1

FIGS. 4A and 4B show longitudinal cross-sectional views of part of anembodiment of a dispenser 201 according to an embodiment of the currentinvention. As in the Examples above, this dispenser 201 comprises ahousing (not depicted) for removably accommodating an assembly Ccomprising a liquid reservoir, a pump and an outlet nozzle. However,unlike the Examples above, the current dispenser 201 exploits a “sidebranch” or “off-axis” architecture (rather than an “in-line”architecture”), as will now be elucidated in more detail.

In FIGS. 4A, 4B, a liquid reservoir 220 is now connected to a shuntingchamber 209. This shunting chamber 209 comprises:

-   -   a first aperture A1 allowing flow access to the liquid reservoir        220;    -   a second aperture A2 allowing flow access to an outlet nozzle        224;    -   a third aperture A3 allowing flow access to a liquid chamber        202,        whereby the third aperture A3 is disposed off-axis with respect        to the first aperture A1 and second aperture A2. The shunting        chamber 209 further comprises a governing device 213 that has        two states, such that:    -   in a first state, a first flow path LI is created between the        first aperture A1 and third aperture A3;    -   in a second state, a second flow path LO is created between the        third aperture A3 and second aperture A2.

Also depicted in FIGS. 4A, 4B is an air chamber 210. This air chamber210 has a dedicated one-way air inlet valve 212 (e.g., a duckbill valve)and air outlet passage 227. The air chamber 210 and liquid chamber 202are disposed in a side-by-side arrangement (unlike the nestedarrangement of FIG. 3, for example). Note that the air inlet valve 212is disparate from the outlet nozzle 224.

The liquid chamber 202 is provided with a pressurizing device 208, andthe air chamber 210 is provided with an ancillary pressurizing device216, both of these pressurizing devices 208, 216 being embodied as, forexample, a bellows or membrane structure.

In the current case:

-   -   the shunting chamber 209 comprises a cylindrical portion 211A;    -   the governing device 213 comprises a plug 211B that is (at least        partially) hollow and that is slidably mounted within the        cylindrical portion 211A;    -   in the first state (FIG. 4A), the plug 211B is in a position        distal from the first aperture A1, and the first flow path LI is        along an external surface 211C of the plug 211B;    -   in the second state (FIG. 4B), the plug 211B is in a position        proximal to the first aperture A1, and the second flow LO path        is through an interior space 211D of the plug 211B via an        entrance 215 in a wall of the plug 211B and an exit 211E in flow        communication with the second aperture A2.

(I) FIG. 4A shows the fill (or charge) state of the dispenser 201. Here,the plug 211B is withdrawn away from aperture A1 so as to allow liquidproduct from the reservoir 220 to flow along a beveled edge 211C of theplug 211B and through aperture A3 and passage 225 into liquid chamber202, as shown by arrow LI. Such flow is instigated by:

-   -   operating the pressurizing device 208 (withdrawing it), so as to        increase the volume of liquid chamber 202;    -   using external mechanical actuation to pull the plug 211B        downward in the cylindrical portion 211A.

Both of these actions may be performed by appropriately connecting items208 and 211B to a suitable actuating organ (not shown here; see item 14in FIGS. 1 and 2)—for example, a lever or button that is allowed torelax outward as a result of a biasing force provided by a springmember.

In a concurrent action, air is drawn into air chamber 210 (shown byarrow AI) through one-way valve 212, by operating the ancillarypressurizing device 216 (withdrawing it), so as to increase the volumeof air chamber 210. This action may also be realized by appropriatelyconnecting ancillary pressuring device 216 to said actuating organ 14.

The plug 211B is engineered in such a manner that, when in thiswithdrawn state, apertures 215 and 217 in its wall are opposed to closedportions of the inner surface of cylindrical portion 211A. In thismanner, air outlet passage 227 is blocked.

(II) FIG. 4B shows the dispensing (or discharge) state of the dispenser201. Here, the plug 211B is urged toward aperture A1 in such a manner asto cause the following concurrent actions/states:

-   -   aperture A1 to be blocked by a portion of a wall of plug 211B,        thus curtailing flow path LI;    -   opening 215 in a wall of plug 211B to mate with aperture A3,        thus allowing a flow of liquid—as shown by arrow LO—out of the        liquid chamber 202 into the interior space 211D of plug 211B,        and ultimately through aperture A2 into outlet nozzle 224;    -   opening 217 in the wall of plug 211B to mate with air outlet        passage 227, thus allowing a flow of air—as shown by arrow        AO—out of the air chamber 210 into the interior space 211D of        plug 211B, and ultimately through aperture A2 into outlet nozzle        224.        Such actions are instigated by:    -   operating the pressurizing device 208 (advancing it), so as to        decrease the volume of liquid chamber 202;    -   operating the ancillary pressurizing device 216 (advancing it),        so as to decrease the volume of air chamber 210;    -   using external mechanical actuation to push the plug 211B upward        in the cylindrical portion 211A.

Once again, all of these actions may be performed by appropriatelyconnecting items 208, 216 and 211B to said suitable actuating organ (notshown here; see item 14 in FIGS. 1 and 2)—for example, said lever orbutton that is now pushed inward.

The flows of liquid product (LO) and air (AO) into the outlet nozzle 224co-mingle to form foam. This is achieved with the aid of a turbulencegenerating member (not depicted) within outlet nozzle 224.

Embodiment 2

FIGS. 5A and 5B show longitudinal cross-sectional views of part of afurther embodiment of a dispenser according to the present invention.This further embodiment is basically identical to that set forth inEmbodiment 1 above, except as regards certain details of the air inletmechanism, which is located within the broken circle in FIGS. 5A and 5B.For purposes of clarity, only the differences w.r.t. the air inletmechanism of Embodiment 1 will be elucidated here.

In the current Embodiment, the duckbill valve 212 of FIGS. 4A and 4B isno longer employed. Instead, part of the wall of the plug 211B has beenprovided with an appropriately positioned cavity 250. In addition,passage 227 now functions as an air inlet passage as well as an airoutlet passage. This set-up operates as follows:

-   -   In FIG. 5A, the plug 211B is in its “withdrawn” state, and the        dispenser 201 is in its filling stroke. In this configuration,        cavity 250 is positioned in such a manner as to form a        connecting channel between passage 227 and passage 252, which        emerges into the outside world. In this manner, air can be drawn        into the air chamber 210 via the route 252, 250, 227.    -   In FIG. 5B, the plug 211B is in its “advanced” state, and the        dispenser 201 is in its dispensing stroke. In this        configuration, cavity 250 is positioned in such a manner as to        blindly face an opposing portion of the wall 211A, which serves        to seal the cavity 250; as a consequence, there is no longer a        connecting channel between passage 227 and passage 252. Instead,        passage 227 now mates with passage 217, allowing air to be        discharged from the air chamber 210 into the nozzle 224.

This embodiment has the advantage of obviating the (relativelyexpensive) duckbill valve 212 of Embodiment 1.

Embodiment 3

Another embodiment of a dispenser according to the present invention isidentical to that set forth in Embodiments 1 or 2 above, but comprisesadditional aspects that will now be further elucidated. For purposes ofclarity, only substantial aspects of the current embodiment that werenot discussed in Embodiments 1 or 2 above will receive attention here.

FIG. 6 shows an end view of part of a dispenser according to the currentinvention. In the Figure, an assembly C′—which comprises a liquidreservoir 220, shunting chamber 209 and outlet nozzle 224—is being putin position, as part of a replacement operation. To this end, thehousing of the dispenser has been opened, and a previous assembly (notdepicted)—of which the liquid reservoir was depleted—has been detachedfrom the liquid chamber 202 and air chamber 210, such that:

-   -   The liquid chamber 202 and air chamber 210 remain as fixtures        mounted to a back wall 234 of the housing;    -   The previous assembly is disposed of

Thereafter, the new assembly C′—of which the liquid reservoir 220 isfull—is put into position. To this end, the shunting chamber 209 of theassembly C′ is provided with members 225′, 227′ that mate with theillustrated liquid passage 225 and air passage 227, respectively. Suchmating can be achieved in various ways that will be readily understoodby a skilled artisan and, by way of example, three of these are depicted(in perspective view) in FIG. 7, as follows:

-   -   In the upper portion of FIG. 7, member 225A′ fits into member        225A via a simple pressure fit. Non-depicted members 227A′ and        227A can (but do not have to) be mated using a similar pressure        fit principle.    -   In the middle portion of FIG. 7, member 225B′ fits into member        225B via a rudimentary click system. Once again, non-depicted        members 227B′ and 227B can (but do not have to) be mated using a        similar click system.    -   In the lower portion of FIG. 7, member 225C′ fits into member        225C via a bayonet coupling. Once again, non-depicted members        227C′ and 227C can (but do not have to) be mated using a similar        bayonet connection.

Returning now to FIG. 6, the liquid chamber 202 and air chamber 210 areembodied as respective bellows 208, 216 in this particular instance. A“head” of each of these bellows 208, 216 (opposite the respectivepassages 225, 227) is affixed to a plate 234′, which is spring-mountedto the back wall 234 of the dispenser using springs 232, which springs232 serve to urge plate 234′ toward wall 234, thus biasing the bellows208, 216 in their extended state. A rod 230A is attached to plate 234′,and this rod 230A passes through an opening in plate 234 such that, bymoving this rod 230A back and forth, the bellows 208 and 216 can beactuated, i.e., caused to contract and extend. Similarly, a rod 230B isattached to plug 211B such that, by moving rod 230B up and down, plug211B can be caused to slide in cylindrical portion 211A. Rod 230A isconnected to an actuating organ (such as item 14 in FIG. 1, or anelectric actuator that is triggered by a proximity detector, forexample), and rod 230B is removably connectable to that same actuatingorgan, the connections involved being embodied in such a manner thatboth rods 230A, 230B can be simultaneously withdrawn or simultaneouslyadvanced using a single motion of said actuating organ. The design ofsuch connections is well within the scope of experience and spectrum ofexpertise of the skilled artisan, and may involve the use of well-knownparts, such as levers, cams, pivots, rack-and-pinion devices, etc.

As depicted in FIG. 6, items 211B/230B are actuated in a verticaldirection, whereas items 234′/230A are actuated in a horizontaldirection, If desired, the depicted construction can be altered suchthat bellows 208 and 216 are now also arranged and actuated vertically,in which case items 234′/230A will also be actuated vertically.

Embodiment 4

FIGS. 8A and 8B show longitudinal cross-sectional views of part of adispenser 301 according to an embodiment of the current invention. Thiscurrent embodiment shows certain similarities with that set forth inEmbodiment 1 and FIGS. 4A/4B above, but also certain differences. Someof these similarities and differences will now be elucidated in moredetail in what follows.

As in Embodiment 1 above, the dispenser 301 of the current embodimentcomprises a housing (not depicted) for removably accommodating anassembly C comprising a liquid reservoir, a pump and an outlet nozzle.Once again, the current dispenser 301 exploits a “side branch” or“off-axis” architecture (rather than an “in-line” architecture”).

In FIGS. 8A, 8B, a liquid reservoir 320 is connected to a shuntingchamber 309 that includes:

-   -   A first aperture A1 allowing flow access to the liquid reservoir        320;    -   A second aperture A2 allowing flow access to an outlet nozzle        324;    -   A third aperture A3 allowing flow access to a liquid chamber        302, whereby the third aperture A3 is disposed off-axis with        respect to the first aperture A1 and second aperture A2. The        shunting chamber 309 further comprises a governing device 313        that has two states, such that:        -   In a first state, a first flow path LI is created between            the first aperture A1 and third aperture A3;        -   In a second state, a second flow path LO is created between            the third aperture A3 and second aperture A2.

Also depicted in FIGS. 8A, 8B is an air chamber 310. This air chamber310 has an air inlet valve (not depicted) and air outlet passage 327.The air chamber 310 and liquid chamber 302 are disposed in anarrangement that is initially concentric, but that subsequently branchesout (bifurcates) into a side-by-side arrangement (not depicted). Theemployed air inlet valve (not depicted) is disparate from the outletnozzle 324. The liquid chamber 302 and air chamber 310 are provided withrespective pressurizing devices (not depicted; but, for example, oftypes such as already shown/discussed above).

In analogy to the situation in Embodiment 1 above:

-   -   The shunting chamber 309 comprises a cylindrical portion 311A;    -   The governing device 313 comprises a (partially) hollow plug        311B that is slidably mounted within the cylindrical portion        311A;    -   In the first state (FIG. 8A), the plug 311B is in a position        distal from the first aperture A1, and the first flow path LI is        along an external surface 311C of the plug 311B;    -   In the second state (FIG. 8B), the plug 311B is in a position        proximal to the first aperture A1, and the second flow LO path        is through an interior space 311D of the plug 311B via an        entrance 315 in a wall of the plug 311B and an exit 311E in flow        communication with the second aperture A2.        However, the manner in which the shunting chamber 309 and        governing device 313 cooperate in order to open and close (allow        and curtail) the various flow paths LI, LO—and also AO (see        below)—is different to the scenario set forth in Embodiment 1        above, as will now be explained.

(i) In the current set-up, an upper portion of the plug 311B is providedwith an external, circumferential lip 402 that—in the abovementionedfirst state (FIG. 8A)—is brought into contact with an internal surfaceof an upper element 404 of cylindrical portion 311A. This upper element404 has a mildly tapering interior surface, and is made of mildlyflexible material (such as PE, for example), so that, as the plug 311Bis withdrawn downward, the lip 402 establishes a good seal with theinternal surface of element 404, thus curtailing any flow of liquidproduct past the lip 402. As such, the only available flow path forliquid product is along the trajectory LI into the liquid chamber 302.

In a similar manner, an external, circumferential lip 502 on a lowerportion of the plug 311B cooperates with an internal surface of a lowerelement 504 of cylindrical portion 311A. Said lower element 504 itselfcontains an internal, circumferential lip 506. In the situation shown inFIG. 8A, the lips 504 and 506 abut against one another, thus forming aseal that curtails flow of air past the lips 504/506.

(ii) In the scenario depicted in FIG. 8B (the abovementioned secondstate), the plug 311B has been displaced upward w.r.t. the cylindricalportion 311A. In this state:

-   -   Aperture A1 is sealed. Such a seal is realized by abutment of an        outer surface 602 of the plug 311B against an inner surface of a        capping element 604 of cylindrical portion 311A, the capping        element being made of mildly flexible material.    -   Liquid product flow path LO is opened, since lip 402 is now        pulled out of contact with the mating inner surface of upper        element 404.    -   Air flow path AO is opened, since lips 504 and 506 are no longer        in abutment.

In the current embodiment, air following path AO ultimately enters theinterior space 311D of the plug 311B via a castellated structuredisposed about the cylindrical axis of the plug 311B. In so doing, itcommingles with liquid product following path LO, thus forming a (pre-)foam that can subsequently be refined by passage through one or moreturbulence generating members (not depicted) within outlet nozzle 324.

1. A method of adjusting the structure and operation of a dispenser fordispensing a fluid product, comprising a housing for accommodating anassembly, the assembly comprising: a liquid reservoir, for containing aliquid product; a pump, connectable to the reservoir, for dispensing thefluid product using the liquid product as an input; an outlet nozzle,serving to convey and dispense the fluid product from the pump; wherebythe pump comprises: a liquid chamber, for containing a dose of theliquid product, obtainable from the liquid reservoir; a compressor,which allows liquid product to be drawn into or expelled from the liquidchamber, wherein the dispenser is further provided with a shuntingchamber comprising: a first aperture allowing flow access to the liquidreservoir; a second aperture allowing flow access to the outlet nozzle;a third aperture allowing flow access to the liquid chamber, and beingdisposed off-axis with respect to the first and second apertures, themethod comprising: disconnecting said compressor, which is to bereplaced; substituting said disconnected compressor by a replacementcompressor, wherein the replacement compressor has a differentpressurizing volume to the replaced compressor.
 2. A method of adjustingthe structure and operation of a dispenser for dispensing a fluidproduct, comprising a housing for accommodating an assembly, theassembly comprising: a liquid reservoir, for containing a liquidproduct; a pump, connectable to the reservoir, for dispensing the fluidproduct using the liquid product as an input; an outlet nozzle, servingto convey and dispense the fluid product from the pump; whereby the pumpcomprises: a liquid chamber, for containing a dose of the liquidproduct, obtainable from the liquid reservoir; a compressor, whichallows liquid product to be drawn into or expelled from the liquidchamber, wherein the dispenser is further provided with a shuntingchamber comprising: a first aperture allowing flow access to the liquidreservoir; a second aperture allowing flow access to the outlet nozzle;a third aperture allowing flow access to the liquid chamber, and beingdisposed off-axis with respect to the first and second apertures,wherein the pump further comprises: an ancillary chamber, for containinga dose of an ancillary substance; an ancillary compressor, which allowssaid ancillary substance to be drawn into or expelled from the ancillarychamber, such that both the liquid chamber and the ancillary chamber areconnectable to the outlet nozzle; which method comprises the followingsteps: disconnecting said ancillary compressor, which is to be replaced;substituting said disconnected ancillary compressor by a replacementancillary compressor, wherein the replacement ancillary compressor has adifferent pressurizing volume to the replaced ancillary compressor.
 3. Amethod according to claim 2, wherein: the ancillary substance is air;the outlet nozzle comprises a member for generating turbulence in liquidand air passing therethrough, and dispenses foam; and replacing theancillary compressor serves to alter the air-to-liquid ratio of the foamdispensed by the dispenser.
 4. A method according to claim 2, wherein:the ancillary substance is air; the outlet nozzle comprises a member forgenerating turbulence in liquid and air passing therethrough, anddispenses foam; the compressor is also disconnected and substituted by areplacement compressor, wherein the replacement compressor has adifferent pressurizing volume to the replaced compressor; thepressurizing volumes of the replacement compressor and replacementancillary compressor are proportionate to the pressurizing volumes ofthe replaced compressor and replaced ancillary compressor, so that thereplacement operation serves to alter the dose of foam dispensed by thedispenser without altering its air-to-liquid ratio.
 5. A methodaccording to claim 1, wherein the disconnected and replaced compressoror ancillary compressor is chosen from the group comprising a bellows, aballoon, a piston, a membrane and an impeller.
 6. A method according toany of claim 1, wherein the disconnected and replaced compressor orancillary compressor is mated to the dispenser via a mating mechanismselected from the group comprising a pressure fit coupling, a clickcoupling and a bayonet coupling.
 7. A method of conducting a maintenanceoperation on a dispenser for dispensing a fluid product, the dispensercomprising a housing for accommodating an assembly, the assemblycomprising: a liquid reservoir, for containing a liquid product; a pump,connectable to the reservoir, for dispensing the fluid product using theliquid product as an input; an outlet nozzle, serving to convey anddispense the fluid product from the pump; wherein the pump comprises: aliquid chamber, for containing a dose of the liquid product, obtainablefrom the liquid reservoir; and a compressor, which allows liquid productto be drawn into or expelled from the liquid chamber, the methodcomprising: opening the housing; removing used parts comprising at leastthe liquid reservoir and outlet nozzle, whilst leaving the liquidchamber and compressor in place in the housing; placing new partscomprising at least a new liquid reservoir and a new outlet nozzle inthe housing; and closing the housing.
 8. A method according to claim 7,wherein: the liquid reservoir and outlet nozzle are respectively fixedto first and second apertures of an interposed shunting chamber; theshunting chamber has a third aperture which can be connected to anddisconnected from the liquid chamber; the used parts additionallycomprise the shunting chamber, which is disconnected from the liquidchamber in order to remove it; and the new parts additionally comprise anew shunting chamber, which is connected to the liquid chamber in orderto place it.
 9. A method according to claim 8, wherein the connectionbetween the shunting chamber and the liquid chamber is effected using amating mechanism selected from the group comprising a pressure fitcoupling, a click coupling and a bayonet coupling.